It's a Windows issue (I don't keep up with windows so perhaps this was changed in the past few years, but I suspect MS hasn't done so due to back compatibility issues).
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation]
"RealTimeIsUniversal"=dword:00000001
It isn't flawless in practice, unfortunately. Internet Time Update no longer works then.